Add the sentinal "no handle" value to the ResumeInst.

Add the sentinal "no handle" value to the ResumeInst.

A value of -1 at a call site tells the personality function that this call isn't
handled by the current function. Since the ResumeInsts are converted to calls to
_Unwind_SjLj_Resume, add a (volatile) store of -1 to its 'call site'.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138416 91177308-0d34-0410-b5e6-96231b3b80d8